Precision divider



Jam?, 1947. 1 T EmYDE- j 2,41317'68 PRECISION DIVIDER Filed April 2o, 1945v I2 sheets-sheet' 1 1 ATruRNEYs' Jan. 7, 1947. T. E. HYDE PRECISION DIVIDER` Filed April 20, 1945 ZVSheBS-Sheeb 2 Mill/7 Patented Jan. 7, 1947 Nil/TED SDYI.' ES PATENT 0F F- IClE,

PRECISION DIVIDER Thomas Edward Hyde,`Raleig h,`N. C.

Application April; 20, 1945, Slerialfllo 589,402v

-claims- 1l Myfpresent inventiomin its broadv aspect, has todofwith' improvements in precision dividers and is a simple, compact,easily operated instrument` wherein a movable needle is actuated by oppositely wound tapes ona shaft to precisely take off spaces.with-reference-to axed'needle and indicate the measurements on alsuitable dial. My. invention is subject rto less margin of error than compass and'otherJ dividers in that actuation of the movableV needle is less subject to unconscious `Avagariesof the operation and the mechanism of the divider is more efficient from-the standpointv of :precision measurements. The dial indicator is so located that accurate readings may be quickly and conveniently made, and the mounting and mechanical control of the operating shaft and the operating knob is such that minute variations for mechanical control are eliminated.

Other and equally important objects and advantages of my invention will be apparent from the following description and drawings, and it is pointed out that changes in form, size, shape, materials, and construction and arrangement ofparts is permissible and within the purview of my broad inventive concept and the scope of the appended claims.

In the drawings, wherein I have illustrated a preferred form of my invention:

Figure 1 is a vertical section; taken on the line l-l of Figure 2 Figure 2 is a transverse section on the line 2-2 of Figure 1;

Figure 3 is a section on the line 3-3 of Figure 1:

Figure 4 is a top plan View;

Figure 5 is a vertical section taken on a line extending through the ports about which the tapes are turned;

Figure 6 is a vertical section taken on a line extending through the movable needle carrying block;

Figure 7 is a detail of the operating shaft showing the pin slot;

Figure 8 is a plan View of the dial;

Figure 9 is a detail section through the dial viewing window, and

Figure 10 is a plan View detail of the dial viewing Window.

In the drawings wherein like characters of reference are used to designate like or similar parts:

The numeral l designates my rectangular casing, which has a bottom 2 and side and end walls 3, and a removable top 4 held in place by corner Screws 5, the ends of which are engaged in corner bosses ton therbottom 2. The casingcmayfloe` formed of plastic or-vothersuitablematerial,and the edges are conveniently roundedozto provide a practical and handy unit. rAtl apoint-rnear; but somewhat toward one end of the casing, .and formed ,on the bottcmis a circular bcssfl having a central cavity with sloping side walls AStore,-V ceive the frustro-conical end of a verticalopem ating shaft Il). The shaft has equallyspaced annular flanges lil abovethe end1i9-to form vspools for reversely`r woundA .steel tapes i12; the= ends of which are attached to: the shaft Vby screws 13'. Above the spools is an enlargedportionJ Igllrha-y.. ing a rib I5. A graduated circular dia1 I6 1s mounted on the enlarged portion I4 and has a notch Il fitting on the rib to prevent independv ent rotation. The shaft II! is journalled in a boss I8 on the top 4 of the casing, and the boss has sloping walls I9 engaged by the sloping inner walls 2li of the enlarged base 2I of an operating knob A, which is attached to the shaft by a transverse pin 22 extending through a slot 23 in the shaft. The slot permits limited movement of the knob axially of the shaft. The knob has an enlarged bore 24 at the top to receive a spring 25 which bears against the enlarged head 26 on the shaft to normally press the knob down so that the sloping Walls I9 and 20 have suicient frictonal engagement to prevent looseness or accidental turning of the shaft. The enlarged base of the knob has an annular slot 2l of about two-thirds the circumference of a circle, and a stop pin 28 on the top 4 and seating in the slot limits the turning movement of the knob and shaft.

The tapes I2 which may be made of steel or other suitable material, have their ends attached :ln the slots of pins 29 carried by a sldable block 30 which has a reduced end 3l fitting in key ways 32 on the bottom 2 of the casing to move parallel with one end of the casing. Each tape is turned about a flanged rotating spool 33, one adjacent each side wall of the casing so .that the form in which the tapes are positioned approximates that of an equilateral triangle, as shown in Figure 2, so that as the shaft is turned in one direction or the other, the respective tapes are Wound and unwound to move the block in the key-Ways in a straight line. The bottom 2 has a straight slot 33a beneath the block and between the keyways through which a movable needle 34 extends, which needle is attached to the block and is the adjustable element of the divider. A xed needle 35-set a little to one side of the needle 34-is mounted in the bottom for cooperation with the movable needle to form my divider, and .the dial I6 is graduated as at 36 to show the measurements indicated by the position of the needles. The top is formed with a Window 31 above the dial which has edge slots 38 to receive a glass pane 39, and a detachable plate 40 permits removal or replacement of the glass.

From the foregoing, it is believed that :the operation and advantages of my invention will be apparent, but it is again emphasized that inter- .pretation of the scope of my invention should only be conclusive when made in the light of the subjoined claims.

I claim:

1. A precision divider, comprising a, casing havlng a removable top, a. shaft rotatably mounted in lthe casing and formed With a pair of spools therein, a pair of tapes reversely wound on the spools, a dial on the shaft, an operating knob fixed on the shaft and having limited sliding movement with respect thereto, means for frictionally wedging said knob in adjusted position, a spring for normally holding the knob in adjusted position, a sliding block to which the free ends of the tape are connected, said block carrying a divider needle, a straight slot in the casing beneath the block through which the divider needle projects outwardly of the casing, a fixed divider needle on the bottom of the casing, and idler spools about which the tapes are trained to be positioned to approximate the sides of a .triangle whereby to move the block and movable needle toward and away from the xed needle in a straight line on turning the knob and shaft.

2. The invention as defined in claim 1 wherein the shaft has equally spaced flanges forming the spools to which the tapes are attached, and wherein the shaft has a conica1 bottom end t- -ting in a depression in a boss having sloping walls .to prevent looseness of the shaft.

3. The invention as defined in claim 1 wherelin the spools about which the tapes are turned are annularly flanged and are rotatably mounted adjacent the sides of the casing, and wherein the movable needle moves in the straight slot in the bottom of the casing.

4. The invention as defined in yclaim 1 wherein the block has a. reduced end slidably fitting in key ways formed on the bottom of the casing and pins on said block above said reduced end to which the free ends of the tapes are attached.

5. vThe invention as defined in claim 1 wherein .the enlarged base of the knob has a semi-circular slot, a stop pin on the top tting in the slot to limit the movement of the knob and shaft, and wherein the .tapes are mounted one above the .other and extend outwardly a-t an angle to the shaft and are turned about idler spools to extend parallel with an end of the casing lto engage and -move the block in a straight line. Y

6.k The invention as defined in claim l wherein the dial is fixed on the shaft above the tape spools and has graduations indicative of the measurements affected by the needles, and wherein the shaft is mounted slightly toward one end of the casing.

THOMAS EDWARD HYDE. 

